Meet Zephyr

An open-source, Java-based plugin framework with smart dependency management, a modular design, and a small footprint.

A Next-Gen, Polyglot Plugin Framework for the JVM

Zephyr makes creating extensible, testable applications a breeze in any JVM language, using any JVM framework


Zephyr intelligently manages all aspects of plugin lifecycle, including classloading, start/stop order, updates, and more


Weighing in at 1.3 MB and requiring only a few KB of memory to run, Zephyr provides powerful features in a tiny, convenient package.


Zephyr plays nicely with whatever JVM languages and frameworks you use. Share framework libraries safely between plugins

Why Use Zephyr?

Zephyr makes creating lightweight, extensible applications simple. Zephyr's classloading is based off of the bulletproof JBoss Modules classloader environment, but provides all the "extras", including:

  • Hassle-free plugin lifecycle management
  • Seamless polyglot language support (run Kotlin plugins from Clojure! We don't care!)
  • Support for your favorite framework.Want to use Spring? Dropwizard? Quarkus? All of them? Do it! We won't frown.
  • Registry/update site included (incubating)
  • Automatically computed fully-parallel operations and minimal operations.Zephyr sips resources by requiring only several KB of memory and 2 dependencies (Picocli and JBoss Modules)